'We believe the same money have been brought back into the country through non-banking channels,' the official added, speaking on condition of anonymity.

Hawala is an illegal exchange of money, including through non-banking channels.

Raju, currently in jail, stunned the corporate world Jan 7 by admitting to a Rs.78-billion (Rs.7,800-crore) accounting fraud. He faces charges of cheating, criminal conspiracy, falsification of records and forgery.